This invention relates to color photography, and more particularly to a method for showing motion in a color photograph.
Over the years a number of devices and methods have been employed to portray motion in a single color photograph. One of the simplest of these known methods involves the use of a time exposure. With a time exposure, the camera is aimed at the subject to be photographed, and the shutter is kept open while the subject is in motion. The resulting photograph shows an object in motion as a blur against a sharply focused background, including the stationary objects. While this method does show which objects in a photograph are moving, it is not very useful for revealing pertinent data concerning the nature of the motion, such as the speed of the object in motion.
Another known method of showing motion in a photograph involves the combining of a series of short-duration flash exposures in which the moving subject is photographed in a series of successive spaced positions. These combined exposures produce a photograph in which the image of non-moving objects are superimposed so that such objects appear as they would in a single exposure, and in which the moving objects appear as a number of sharp, spaced images in the combined photograph, all in the same colors.
Furthermore, it is possible to show motion by combining the two above discussed methods. By combining a high speed flash with a time exposure, an object can be shown sharply by the flash in conjunction with a related blurred image caused by the time exposure.
Another known apparatus and method for showing motion in a still photograph involves the use of a Harris shutter. The Harris shutter, which is described in More Joys of Photography (by the editors of Eastman Kodak Company, Addison Wesley Publishing Company, 1981), involves the use of a number of colored filters which are passed in rapid succession in front of a lens during a time exposure. Any object which moves during the exposure is recorded as spaced images in variegated colors, and the remainder of the scene which does not move is photographed in the natural color. Typically, the Harris shutter makes three exposures of the scene, each through a different colored filter. The reason stationary objects look natural is that the three filters transmit, sequentially, the primary colors in white light, i.e., red, green and blue, and all three images are superimposed. Each of the three filters lets in parts of the light blocked by the other filters, so that the cumulative effect is about the same as if the scene has been exposed without filters. Anything that moved during the exposure, however, will be recorded in multiple colors as spaced images because the moving object's position changes with the changing of the filter. One problem associated with the Harris shutter arises from the difficulty of forming sharply focused images of rapidly moving objects because of limitations on the speed of changing the filters. A Harris shutter device which would be capable of showing high speed movement would probably be costly to construct.
It is therefore a principal object of the present invention to provide a simple apparatus and method for showing movement in a single color photograph without the necessity of providing a Harris-type moving shutter.
A second object is to provide an apparatus and method for showing motion in a single color photograph in which the necessary equipment is relatively inexpensive to construct.
Another object is to provide an apparatus and method for showing motion in a single color photograph which can effectively display the movement of an object in a manner that provides pertinent measurable data concerning the motion, such as the speed.
Still another object of the present invention is to provide an apparatus and method for showing motion in a single color photograph in which sharply focused images of the scene being photographed including moving objects, is produced.